In a surprise announcement, Mayor Michael R. Bloomberg said Thursday that Hurricane Sandy had reshaped his thinking about the presidential campaign, and he announced that he was endorsing President Obama.

Mr. Bloomberg, a political independent in this third term leading New York City, has been sharply critical of both Mr. Obama, a Democrat, and Mitt Romney, the president’s Republican rival, saying that both men have failed to candidly confront the problems afflicting the nation. But he said he had decided over the past several days that Mr. Obama was the best candidate to tackle the global climate change that the mayor believes contributed to the violent storm, which took the lives of at least 38 New Yorkers and caused billions of dollars in damage.

“The devastation that Hurricane Sandy brought to New York City and much of the Northeast — in lost lives, lost homes and lost business — brought the stakes of next Tuesday’s presidential election into sharp relief,” Mr. Bloomberg wrote in an op-ed article for Bloomberg View.

“Our climate is changing,” he wrote. “And while the increase in extreme weather we have experienced in New York City and around the world may or may not be the result of it, the risk that it may be — given the devastation it is wreaking — should be enough to compel all elected leaders to take immediate action.”

Mr. Bloomberg’s announcement is another indication that Hurricane Sandy has influenced the presidential campaign. The storm, and the destruction it left in its wake, has dominated news coverage, transfixing the nation and prompting the candidates to halt their campaigning briefly.

10. I hope it impacts some Republicans as well.

11. Surprise! It's Real!

Too many officials in high places are having to learn this the hard way. Some will undoubtedly remain deniers of reality. Either way, the tipping point that is approaching cannot be held off indefinitely. I certainly hope that we're not past that point.